Some of the active ingredients for use in the method for controlling weeds according to the present invention, methods of preparing same and their pharmaceutical use as antifungal agents are known from U.S. Pat. No. 3,485,917. Further, some of these compounds were described as active agents in a method for inhibiting bud growth in U.S. Pat. No. 3,873,297. The majority of compounds of formula (I) are novel and have especially been developed to be used in the method of this invention.